Background: The use of inhaled steroids is common in the treatment of bronchial asthma in children. Aim: To assess adrenocortical function in children with severe asthma receiving inhaled budesonide for six or more months. Material and methods: Children with severe asthma that required 800 µg/day or more of inhaled budesonide and that did not required systemic steroids for more than six days in the last four months to control their disease, were studied. Serum cortisol was measured one hour after administration of 0.25 mg of ACTH (Cosyntropin®) intravenously. The test was considered normal if post stimulation serum cortisol was over 18 µg/ml. Results: Twenty children (aged 5 to 14 years, 15 males), were studied. The stimulation test was normal in 17 children. Conclusions: Alterations in adrenal function are present in a small proportion of asthmatic children who require 800 µg/day of inhaled budesonide